The hepatitis B virus belongs to the family of hepadnaviridae. It can cause acutely and/or persistently or progressively chronic diseases. Many other clinical manifestations in the pathological morphology are also caused by HBV—in particular chronic hepatitis, cirrhosis and hepatocellular carcinoma. Additionally, coinfection with hepatitis D virus may have adverse effects on the progress of the disease.
The conventional medicaments approved to be used for treating chronic hepatitis are interferon and lamivudine. However, the interferon has just moderate activity but has an adverse side reaction. Although lamivudine has good activity, its resistance develops rapidly during the treatment and relapse effects often appear after the treatment has stopped. The IC50 value of lamivudine (3-TC) is 300 nM (Science, 2003, 299, 893-896).
Deres, et al, have reported heteroaryl-substituted dihydropyrimidine (HAP) compounds which were represented by Bay41-4109 and Bay39-5493, and these compounds play a role in blocking HBV replication by preventing the proper formation of viral core particles (nucleocapsids). Bay41-4109 has demonstrated better drug metabolic parameters in clinical study (Science, 2003, 299, 893-896). The study of these compounds' mechanism of action indicated that through reacting with 113-143 amino acid residues of a core protein, heteroaryl-substituted dihydropyrimidine compounds have changed the angle between dimers which can form nucleocapsids, and led to forming unstably expanded nucleocapsids, which accelerate the degradation of the core protein (Biochem. Pharmacol., 2003, 66, 2273-2279).
New and effective antiviral compounds are urgently needed, especially for treating and/or preventing HBV infection.